In general, an ABS resin obtained by graft-copolymerizing styrene and an acrylonitrile monomer with a butadiene-based rubbery polymer has excellent impact resistance and moldability and also, excellent mechanical strength, thermal distortion temperature or the like, and satisfactory coloring properties and thus, is widely used for an electrical/electronic appliances, automotive parts, office supplies, and the like. However, the ABS resin has chemically unstable double bonds in its rubber component and thus, has a problem of very weak weather resistance, since the rubber component is easily aged by an ultraviolet (UV) ray. An attempt to improve the problem by adding an ultraviolet stabilizer thereto during the extrusion process has been made, but has a little effect and still causes weak properties about the ultraviolet (UV) ray. Accordingly, various methods of improving this problem have been suggested, and particularly, a method of using a chemically stable acrylic-based rubber instead of a butadiene rubber, a method of using a rubbery polymer obtained polymerizing butadiene and an acrylic-based polymerizable monomer and the like have been widely used.
The ASA (acrylate-styrene-acrylonitrile) graft copolymer resin obtained by graft-copolymerizing the styrene and the acrylonitrile monomer into the acrylic-based rubbery polymer has been widely used for an interior/exterior part for vehicles, farm equipments and the like or particularly electrical/electronic appliances requiring weather resistance.
The ASA resin has no chemically unstable double bonds and thus, no particular effect on weather resistance. However, the ASA resin has a problem of deteriorating impact resistance. In order to solve this problem, a method of increasing a diameter of a rubber particle, decreasing a gel content of the rubbery polymer, or the like has been used. However, these methods deteriorate appearance properties such as gloss as well as have difficulties in controlling properties of a graft copolymer. In addition, in order to improve impact resistance, gloss and the like, a method of preparing each acrylic-based rubbery polymer having a different average particle diameter and mixing them is used but has no sufficient result.
The ASA resin is a terpolymer of acrylate-styrene-acrylonitrile and has excellent weather resistance, chemical resistance, and thermal stability and thus, is widely used for outdoor electrical/electronic parts, automotive parts, building and sports goods, and the like but lacks of coloring properties and impact resistance at a low temperature or room temperature and is extremely limitedly applied to parts for electrical/electronic appliances, farm equipments, automotive parts. Recently, researches on preparing a weather resistant resin having small property change depending on a temperature condition and excellent coloring properties to satisfy these requirements have been made.
In general, the ASA resin is also called to be a ASA terpolymer and variously used due to excellent weather resistance and chemical resistance and in particular, is widely used for an object mainly used outside and requiring weather resistant discoloring, chemical resistance, thermal stability and the like, for example, electrical/electronic parts, a building material, a material for a farm equipment, an ASA/ABS double sheet, profile extrusion, a road sign, outdoor goods, building/interior goods, leisure/daily supplies, sports goods, automotive parts, and the like. The ASA resin is mainly applied to a satellite antenna, a kayak paddle, a chassis joiner, a door panel, a side-mirror housing and the like. In particular, the ASA resin is increasingly demanded as a building material due to recent restriction about a vinyl chloride resin and gentrification in a building material market and gradually more widely used as a chassis profile and a roof finishing material as well as a conventional chassis joiner.
Accordingly, development of an ASA resin having excellent weather resistance, impact resistance, and coloring properties is required.